If Restore Previous Session is grayed out then either:

• Session was already restored
• There is nothing to restore

If the history menu isn't reflecting a tab you just closed in the same window or another window you just closed, and your sessionstore preferences look normal, then the session history feature is not working correctly.

In that case, I would suggest a "clean" reinstall. I'm not familiar with Linux folder structures, but basically you would rename the current program folder (only, don't do anything to your profile folder) and then install again.

Yes, I could create a couple tabs, close FF, then reopen and no session-restore options, though they are in the history.

I could also open a couple tabs, close them, see them in history, but the items listed remain greyed out

I tried creating a new profile and using the FEBE addon to bring in the usable gui. Same issue.

Changed the version running. That got those items not greyed-out. It's been an hour and no crash yet, so hopeful this version for Linux is stable.